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Natural and Intentional Electromagnetic Interference (IEMI) on a network's communications nodes can cause combinations of short-term upset, long-term upset and permanent damage to equipment. In this paper we provide new theoretical principles based on random graph theory and percolation theory to evaluate the resilience of large random geometric ad-hoc networks formed with non-directed and directed...
Iris recognition is increasingly important, especially in critical areas such as airports and places of border control. For these locations, the targets are inherently non-cooperative, and it is then necessary to detect at ranges well beyond the noseon range for cooperative targets. In this paper, we reexamine some of the basic electromagnetic issues of using LED or laser sources in relation to their...
In a previous investigation [1–3] a theory for detecting complex objects embedded in complex dielectrics using the mathematical structure of the dyadic Green's function [4] was developed. The purpose of that study was to improve upon existing approximations for predicting the electromagnetic fields generated by and onto canonical structures such as loops and dipoles in conducting media. In this study,...
This paper examines the applications of statistical physics-stochastic processes, ergodic principles, the use of nonlinear dynamic state equations and chaos, and the Wiener-Khintchine theorem to better explain how Intentional ElectroMagnetic Interference (IEMI) disrupts the performance of feedback and hybrid electronic systems such as control systems, power electronics and SCADAs. The origin of spurious...
We consider four effects relevant to the determination of the ratio of radar signal to clutter and noise. These effects are atmospheric turbulence, target fluctuations based on the Swerling models, zero-mean Gaussian background and receiver noise, and lognormal-distributed clutter. Radar return signal levels are affected by target fluctuations and atmospheric turbulence, characterized by a variant...
Over the last few years, members of the electromagnetics community have used two types of models to investigate the differences in upset thresholds for multiple microsecond pulses compared to single or few shot short-pulse illuminations of complex electronic equipment. These models are: communication theory models and hybrid models. After reviewing and contrasting these models, we use a hybrid model...
Exact three-dimensional solutions for secondary sources using the unique mathematical properties of the dyadic Green's function are presented. Applying the radiation condition, this analysis additionally focuses on cases where the lateral distance between source and field point is much greater than the wavelength.
A calculation model to estimate data channel degradation due to the influence of periodically repeating voltage pulses is presented in this paper. These periodically repeating voltages can be caused by accidental or intentional disturbances that are either injected onto a communications line or coupled to the line by a radiated field. Comparative analysis of the influence of different pulse disturbances...
In this paper we examine a control strategy that improves the probability of recovery of strongly coupled infrastructures subsequent to a postulated large-scale disruption and damage event. We study the electric power grid and public data network as notional examples. We show that very general properties lead to the possibilities of both recovery and collapse. We model the infrastructures as sets...
Impulse radiating antennas are noted for their large on-axis radiation field. Little attention has been paid to their non-radiation inductive and electrostatic components which become dominant at small ranges. These fields may become important sources of electromagnetic interference electronic equipment located at small ranges. This paper provides a detailed derivation of the inductive and electrostatic...
Sources and related components to support high power electromagnetic (HPEM) ultra-wideband systems are of growing importance. The ultra-wideband domain is characterized by a bandwidth ratio, br=(f high/flow)>10 with a nominal center frequency in the GHz range. Shielded microstrips and coplanar waveguides may find increasing application for developing advanced ultra-wideband systems. Dielectric...
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